Integration system for lifting surfaces semi-parts in aircrafts

ABSTRACT

The lifting surface consists of a torsion box capable of bearing aerodynamic and inertial loads, and the semi-parts ( 1, 1 ′) comprising it are connected together with joining means conventionally consisting of a rib in one piece in its plane of symmetry, the final assembly of said lifting surfaces requiring some inspection openings or holes for being able to gain access to the corresponding joints. The invention provides other joining means which avoid that rib and which consist of a plurality of bars ( 2 ) modularly arranged in the manner of a lattice, in such a is way that the required amount of said inspection holes is reduced, and a sequential assembly connecting the upper and lower ends of the bars ( 2 ) is facilitated.

OBJECT OF THE INVENTION

As stated in the title of this descriptive specification, the present invention relates to an integration system for semi-parts of lifting surfaces in aircrafts, the aim of which consists of providing a new system of attachment of boxes in the plane of symmetry of the lifting surfaces of airplanes or aircrafts. This is a design solution allowing the assembly of boxes without any need to make inspection openings or holes for accessibility in certain linings.

The invention comes within the technical sector of aeronautics, and specifically to the assembly of the semi-parts making up a lifting surface in airplanes or aircrafts; being the basic aim of the invention to reduce the amount is of inspection openings or holes necessary for assembly, maintenance and revision operations.

By means of the invention, problems of accessibility in the final integration of the semi-boxes are solved, maintaining the structural efficiency of the array and simplifying the design, manufacture and assembly of components, with the consequent final saving in economic resources.

BACKGROUND OF THE INVENTION

The structural core of a design of lifting surface consists of a torsion box capable of bearing the aerodynamic and inertial loads that it is subject to. The lifting surfaces are typically designed by means of two semi-boxes joined in their plane of symmetry, as in the case of horizontal stabilizers, or two semi-boxes and a third central box joining them, as in wings or horizontal stabilizers. A separate case is structures formed from a single box, such as ailerons, flaps, rudders, elevators and vertical stabilizers. The final assembly of lifting surfaces requires the necessary inspection openings (windows or orifices) for adequate access to the attachment zones. Said inspection openings imply an appreciable reduction in the structural efficiency of the zones in their vicinity. This, in turn, implies an increase in weight with respect to an ideal structural configuration.

The attachment of semi-boxes is usually done by means of a rib as a whole in its plane of symmetry. This type of installation is possible if the design considers the following aspects:

-   -   The lifting surface is provided with fuel tank, which entails         access holes (manholes or handholes) in the lower part of the         lining in order to carry out assembly/maintenance tasks. Access         is also guaranteed with the support of inspection openings in         spars or with removable spars. From the viewpoint of the design,         manufacture and assembly, each inspection opening or the         capacity to dismantle an element implies a major complication.         Moreover, each inspection opening implies an increase in the         weight of the structure.     -   The size of the lifting surface is sufficiently small to allow         access to assembly operations from the outside.

We do not know of any integration system for semi-parts existing in the is state of the art like those that have been referred to, in which the conventional in one piece rib mentioned above is replaced with bars in a manner of a lattice, as is done by the present invention.

DESCRIPTION OF THE INVENTION

In order to achieve the objectives stated above, the invention consists of an integration system of lifting surfaces semi-parts in aircrafts, where the lifting surface consists of a torsion box capable of bearing aerodynamic and inertial loads, and the semi-parts comprising it are connected together with means of attachment which conventionally consist of a rib in one piece in its plane of symmetry, the final assembly of said lifting surfaces requiring some inspection openings or holes for being able to gain access to the corresponding attachments.

As a novelty, according to the invention, the means of attachment consist of an array or plurality of bars arranged in modular fashion in the manner of a lattice, such that the necessary number of said inspection openings is reduced and a sequential assembly connecting the upper and lower ends of the bars is facilitated.

According to the preferred embodiment of the invention, the bars present certain longitudinal ends with zones of attachment and a transverse section in the shape of a “T”. Moreover, in said preferred embodiment, the mentioned bars are made of carbon fiber, titanium or a combination of said materials or others with high resistance to corrosion.

In the preferred embodiment of the invention, the bars in a manner of a lattice that have been mentioned before are attached in the corresponding assembly to a central support made of titanium, towards both sides of the plane of symmetry alternatively, thereby facilitating quasi-symmetric conditions in the point of attachment which reduce the number of brackets that are needed.

Moreover, according to the preferred embodiment of the invention, in the arrangement of the bars in a manner of a lattice which connect said semi-parts, it is possible to establish a single wide zone of access conforming the inspection openings or orifices, which can be temporary, being used solely in is the assembly phase, and which can be closed afterwards with a piece provided with windows for permanent access.

With the structure that has been described, the invention presents the following main advantages:

The invention solves the problem of accessibility in the final integration of the semi-boxes maintaining the structural efficiency of the array and simplifying the design, manufacture and assembly of components, with the consequent final saving in economic resources. Furthermore, by means of the invention it is possible to introduce a large number of bars, since the number of attachment points is reduced, increasing the resistance and rigidity of the ensemble. Moreover, the design of the invention permits the load between bars to be transmitted directly without any need to load the corresponding metal support or frame, thereby reducing undesirable bending effects concentrated in it. Other advantages of the invention consist of the fact that for the assembly it is not necessary to make and that the number of inspections necessary over the life of the aircraft for corrosion reasons is minimized. It can be concluded that the main advantage of the invention lies in the fact that using bars in a manner of a lattice as attachment system for boxes significantly reduce the number of inspection openings necessary for its assembly.

Below, in order to facilitate a better understanding of this descriptive specification and forming an integral part thereof, some figures are attached in which the object of the invention has been represented by way of illustration and non-limiting.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. Represents a perspective and partial view of some semi-parts connected by some bars in a manner of a lattice, by means of a system embodied according to the present invention.

FIG. 2. Represents a perspective view showing in greater detail one of the bars referred to in FIG. 1 above, showing the zones of attachment of its ends.

FIG. 3. Represents a perspective view showing an access in the assembly phase of the corresponding semi-parts in a system like that of FIG. 1 above.

FIG. 4. Represents a perspective view analogous to that of FIG. 3 above, once the said access in the assembly phase has been closed with a piece that includes permanent access windows.

FIGS. 5 and 6. Are figures belonging to the state of the art, and which represent respective front and rear perspective views of a conventional rib with flat core which is currently used for integration of the semi-parts for lifting surfaces in aircraft.

DESCRIPTION OF AN EXAMPLE OF EMBODIMENT OF THE INVENTION

A description is made forthwith of an example of the invention making reference to the numbering adopted in the figures.

So, the integration system for lifting surfaces semi-parts in aircrafts of the present example is applied to a lifting surface which consists of a torsion box and which has a first semi-part 1 and a second semi-part 1′ connected together by means of some bars in a manner of a lattice 2 arranged in a modular fashion, as represented in FIG. 1.

Said bars in a manner of a lattice 2 replace the conventional whole rib 6 in one piece shown in FIGS. 5 and 6.

The assembly of lifting surfaces formed by semi-parts 1, 1′ requires inspection openings or orifices for assembly and maintenance which are minimized by means of said arrangement of bars in a manner of a lattice 2. So, according to the present example, the arrangement of the bars in a manner of a lattice 2 facilitates the establishing of a single and wide access zone 4, shown in FIG. 3. This access zone 4 can be temporary, being used solely in the assembly phase, in order to be closed afterwards with a piece provided with windows for permanent access 5, as has been represented in FIG. 4.

On the other hand, according to the present example, in the corresponding assembly the bars in a manner of a lattice 2 are attached to a central support made of titanium, towards both sides of the plane of symmetry alternatively, thereby facilitating quasi-symmetric conditions in the point of attachment which reduce the number of brackets that are needed.

In the present example, each one of the bars 2 has longitudinal ends with zones of attachment 3 and a transverse section in the shape of a “T”. Additionally, in the present example, the bars 2 are made of materials with high resistance to corrosion. Examples of such materials that are especially resistant to corrosion are carbon fiber and titanium, which are also galvanically compatible with each other. 

1. INTEGRATION SYSTEM FOR LIFTING SURFACES SEMI-PARTS IN AIRCRAFTS, where the lifting surface consists of a torsion box capable of bearing aerodynamic and inertial loads, and the semi-parts (1, 1′) comprising it are connected together with means of attachment conventionally consisting of a rib in one piece in its plane of symmetry (6), the final assembly of said lifting surfaces requiring inspection openings or holes for being able to gain access to the corresponding attachments; wherein the means of attachment consist of a plurality of bars (2) modularly arranged in the manner of a lattice, in such a way that the required amount of inspection openings is reduced and a sequential assembly connecting the upper and lower ends of the bars (2) is facilitated.
 2. INTEGRATION SYSTEM FOR LIFTING SURFACES SEMI-PARTS IN AIRCRAFTS, according to claim 1, wherein the bars (2) present longitudinal ends with zones of attachment (3) and a transverse section in the shape of a “T”.
 3. INTEGRATION SYSTEM FOR LIFTING SURFACES SEMI-PARTS IN AIRCRAFTS, according to claim 2, wherein the bars (2) are made of material selected from the group consisting of carbon fiber, titanium, a combination of said materials or others with high resistance to corrosion.
 4. INTEGRATION SYSTEM FOR LIFTING SURFACES SEMI-PARTS IN AIRCRAFTS, according to claim 3, wherein the bars (2) modularly arranged in the manner of a lattice are attached in the corresponding assembly to a central support made of titanium, towards both sides of the plane of symmetry alternatively, thereby facilitating quasi-symmetric conditions in the point of attachment which reduce the number of brackets required.
 5. INTEGRATION SYSTEM FOR LIFTING SURFACES SEMI-PARTS IN AIRCRAFTS, according to claim 1, wherein in the arrangement of the bars (2) in a manner of a lattice connecting the said semi-parts (1, 1′), it is made possible to establish a single and wide zone of access (4) conforming the inspection openings or orifices, which can be temporary, being used solely in the assembly phase, and which is closed afterwards with a piece provided with windows for permanent access (5).
 6. INTEGRATION SYSTEM FOR LIFTING SURFACES SEMI-PARTS IN AIRCRAFTS, according to claim 2, wherein in the arrangement of the bars (2) in a manner of a lattice connecting the said semi-parts (1, 1′), it is made possible to establish a single and wide zone of access (4) conforming the inspection openings or orifices, which can be temporary, being used solely in the assembly phase, and which is closed afterwards with a piece provided with windows for permanent access (5).
 7. INTEGRATION SYSTEM FOR LIFTING SURFACES SEMI-PARTS IN AIRCRAFTS, according to claim 3; wherein in the arrangement of the bars (2) in a manner of a lattice connecting the said semi-parts (1, 1′), it is made possible to establish a single and wide zone of access (4) conforming the inspection openings or orifices, which can be temporary, being used solely in the assembly phase, and which is closed afterwards with a piece provided with windows for permanent access (5).
 8. INTEGRATION SYSTEM FOR LIFTING SURFACES SEMI-PARTS IN AIRCRAFTS, according to claim 4, wherein in the arrangement of the bars (2) in a manner of a lattice connecting the said semi-parts (1, 1′), it is made possible to establish a single and wide zone of access (4) conforming the inspection openings or orifices, which can be temporary, being used solely in the assembly phase, and which is closed afterwards with a piece provided with windows for permanent access (5). 